A dependable, economical and compact variable AC voltage supply manufactured especially for the vibratory feeder, fan, pump, heating, and lighting industries. All models feature single-phase AC input and fully variable AC output. The enclosed version comes with a rugged housing, power on/off switch, power on indicator lamp, front access fuse, as well as convenient input and output cords and plugs. The heart of the control is a triac fired in a manner to adjust phase and thereby vary speed. The 55 Series is designed to work with shaded pole, permanent split capacitor, permanent split-phase, universal motors or any resistive load. It is not designed for capacitor start motors.